Alveolar canal extension: risk probability with implants?

The chances are that numbness will prevail. Doubt the patient would like it.

The question whether this is a branch or a loop. Loops generally appear as two distinct nerves on the sagittal view. In fact one of the slices clearly shows it as a branch. I doubt any numbness would occur.

Could you be more specific as to the position you want to place your implants. The Inferior Alveolar Nerve always extends to the mid line through the mandibular incisive canal, some call that portion of the nerve the Mandibular Incisive Nerve. This portion of the nerve enervates the Canine, Lateral and Central Incisors, it has nothing to do with the innervation of the lip or any other soft tissue. The Inferior Alveolar Nerve also has a branch that exits through the Mental Foramen called the Mental Nerve. It enervates the lip and the soft tissue of the chin. Paresthesia and Hyperesthesia are the main concerns when damaging the the Inferior Alveolar Nerve before it exits the Mental Foramen or also damaging the Mental Nerve . In certain occasions hyperesthesia can be caused by placing the implant close to the Mandibular Incisive Nerve. Most of the time this can be prevented by staying away from the nerve or drilling through the nerve.

As Raul pointed out, you need to specify where in this edentulous mandible you intend to place the implants. It seems there is enough height for placing 8-10mm implants without hitting the nerve.

The risk for transecting the incisive nerve is not parasthesia, but rather dysesthesia from Wallerian degeneration of this branch of V3. The most common presentation is a burning sensation. If teeth are present you also run the risk of devasciularization of the teeth on this side. RJM

Thank you dear colleagues for your comments. my intentions are to insert the implants in the inter foramina zone. for an overdenture ancored to ball attachments or an all on four fixed denture. as not all your opinions are concordant about the upcoming symptomes, I would like to ask you if any of you has a personal experience with a case like this. unfortunately ,as you all know , not always the theories will mach perfectly the reality of clinical life. Thank you very much.

I have done this many times, close to this so-called mental loop or through it. I believe the areas of true danger are the mental foramina and posterior to it. To my knowledge my patients have experienced no numbness or burning sensation. But ideally one avoids it.

This is the Incisive nerve which is a terminal branch of the inferior alveolar nerve. In my practice , I don't take in consideration the presence of this nerve, either in tumor or genioplasty and by extension in Oral Implantology. Even in the literature, there is no case report of incisive nerve traumatic neuropathy. In your case, you don't even have the probability of reversible hypoesthesia of the anterior teeth, as it is an edentulous case. However, what you have to do is to leave a security distance of 5 to 6 mm between the most distal implant and the mental foramen in order to prevent an injury to the mental nerve which can provoke neurological symptomes in the lower lip and chin area.

Done it many times. No symptoms

Every patients has this branch. For some patient it is very prominent, for others are not. you can't avoid this branch . Best thing is Its main role is supply to the incisor teeth, and a tiny branch come out thorough the lingual side and role is not very clear. For edentulous case the patient has no complain even after injury. Some patient fell pain during drilling, its may be due to injury of that nerve. but no complain after healing phase . paresthesia, hyperesthesia are not the issue in this case. Burning sensation can be develop but I never encountered. So I think you should do otherwise another doctor will definitely do.

Do it or somebody else will? What say you as to this rationalization?